Electrode suspension means



Patented Oct. 3, 1933 7 1, 2 4 l ELECTRODE SUQPENSION MEANS Jean Grole,Taraseon Sm- Ariege, France, aslimo:- to Det Norske Aktieaeuab forElektrokemisk. mama,

Application July and in Oslo, Norway 18, 1931, Serial No. 551,807,Norway July 23, 1930 7 Claims. -(Cl. 13-13) This invention relates to anelectrode suspension means, particularly adaptable to electrodes of thetype which are baked in the furnace in which they are used (1. e., theso-ealled Soderberg electrodes). Ordinarily, with this type ofelectrode, a holder is used which surrounds the electrode, and whichcomprises sections or gripping means which engage the electrode andpress upon the same on the more or less baked zone of the electrodewhich occurs above the top of the furnace. Since different conditions,and diiferent types of furnaces in which the electrodes are used,require varying electrode consumption, such consumption may vary betweenII for instance, one-half inch to forty inches per day, and theelectrode consumption makes it necessary to feed the electrode to thefurnace from time to time as it is consumed. The feeding of theelectrode is usually accomplished by looseningthe -grip holder until theelectrode, under the influence of its own weight, slips through theholder as far as is desired, whereupon the grip holder is againtightened.

The use of the grip holders of the ordinary type is accompanied at timeswith certain disadvantages, particularly where the consumption of theelectrode requires frequent feeding, or where the installation is suchas to make diflicult the feeding of the electrode, or where the spacearound the electrode is not adapted or available for the usual holder.In the use of electrodes in furnaces for producing aluminum, and forsimilar purposes, for example, the electrodes are usually of largedimensions, for instance, eighty-five inches in diameter, and weigh,often times, in

the neighborhood of fifteen tons. In such an installation, the gripholder is a heavy and complicated device, requiring a series of movableparts in order to give satisfactory results, and these movable partsusually are operated separately when the electrode is to be allowed toslip, as otherwise the electrode may have a tendency to slide more onone side than on the other, and thus become disaligned with the furnace.Further, in this type of installation, the baking of the electrodeproceeds only a comparatively short distance upwardly in the electrode,so that the grip holder needs to be placed close to the surface of thebath. Since the temperature of the bath is usually relatively low, theelectrode paste, even adjacent the surface of the bath is often timesnot as thoroughly baked as in other installations where the temperatureis higher, and these conditions have given rise in some instances tofurther disadvantages which are caused by the grip holders deforming theelectrode, or causing cracks or breaks therein. A further disadvantagewith the use of the grip holders as suspension means for the electrode,is that it sometimes interfers with the means for introducing currentinto the electrode, particularly where the current is supplied throughcontacts which extend into the electrode through the casing from theoutside, such for instance, as in the manner disclosed in U. S. PatentNo. 1,751,695, to Westly.

One of the objects of this present invention is to provide a suspensionmeans which does away with the disadvantages as outlined above, whichaccrue to the grip holder type of electrode-suspending means. I

Another object of the invention is to provide a suspension means,particularly adaptable for the type of electrodes which are baked in thefurnace in which they are used in which the suspending means is attacheddirectly to the metallic casing, or to the ribs or other extensions withwhich it is provided, and supports the electrode without bringingpressure to bear on the electrode paste.

A further object of the invention is to provide an electrode suspensionmeans which may support the electrode from the upper part thereof, at apoint well above the furnace, so as to leave the portion of theelectrode above the path as free as possible of obstructions, whereby toafford plenty of room for a workman to manipulate his tools whenbreaking through the crust of the bath, for instance, in eliminating theanode effect, or in mixing new alumina into the bath. It will beunderstood that the furnace crucibles are often quite narrow withrespect to the electrode diameter, so that this work is rendereddiflicult, particularly if the electrode holder is placed just above thesurface of the bath, as is the case with the grip holder type ofsuspending means.

A further object of the invention is to provide an electrode-suspendingmeans which is adapted to engage the ribs or other extensions of theelectrode, and thereby support the electrode, so that the electrodecasing can be lengthened by welding or by the addition of new sections,without interfering with the holder.

With theseand other objects in view which will become apparent as thedescription proceeds, reference is made to the accompanying drawing, inwhich one of the forms that the invention may take is illustrated, andin which,--

Figure 1 represents an elevational' view, partially in section, of aninstallation made according tomy invention. .119

gage between tion, so that tional view of an installation showing adifferent form of electrode rib.

Figure 3 represents a horizontal sectional view through an electrode.

Figure 4 represents a fragmentary plan view, partially in section, ofthe installation shown in Figure 1.

Figure 5 represents an enlarged fragmentary plan view showing one "ofthe suspension clamps.

In the drawing, an electrode is indicated at 1, in an installationsuitable for the electrolytic production of aluminum. The electrodecasing is indicated at 2, and at 3 are indicated the external ribs bywhich the electrode may be suspended accordingto my invention. Theseribs on the inner side of the casing 2, projectinwardly into the pasteof the electrodev as at 4, and the inwardly projecting portions of theribs may be of saw-tooth arrangement, as indicated, which afford a goodconnection between the ribs and the lower baked portion of theelectrode, to 1 thereby adequately support the electrode mass within thecasing. The ribs may either be integral with the casing, or they may befixed thereto by welding, or in other suitable manner.- The casingitself, it will be understood, may be made in different ways, forinstance, by using rolled sheets, or by casting the sheets in suitableshape and size from aluminum. The sections of the casing may beconnected together by means of plates 3 which may overlap adjoiningportions of the ribs 3 and may be secured in suitable manner as forinstance, by bolts or rivets.

A suspension frame is indicated at 5, and this frame may be suspendedfrom the platform 8,

by means of the screw hoists 9, the latter being adapted for rotationthrough suitable gearing 10, for raising or lowering the suspensionframe, and with it the electrode, through the instrumentality of theclamping means 11. Each of the clamping means comprises a pair of plates12 provided with webs or bases 13 by which they are pivotally mounted asat 14 on the suspension frame 5, at

suitable points around the electrode. The clamp plates 12 at'their innerends are adapted to enthem the external ribs 3 of the electrode casing,and bolts or other suitable tightening means 15 connect the clampingplates together at points outside of the ribs. In this way the clampsgrip the ribs with sufficient tightness to sustain and support theelectrode, the weight of the latter being transmitted through the clampsto the suspension frame 5 and thence through the screw hoists 9, to theplatform 8.

As the electrode is consumed at its lower end, it may be lowered fromtime to time as desired, by operating the screw hoists, untilthe framegets so close to the furnace as to interfere with the properintroduction and removal of the inserts 16 which are utilized forintroducing the current. The clampsv 11 may then be loosened,thesuspension frame raised, and the clamp reattached to the ribs higherup on the electrode. During this change, the electrode may be suspendedin suitable manner, for instance, through the chainsuspension meansindicated generally at 17, which may be attached to a crane, notillustrated, which thus supports the electrode while'the suspensionmeans is being shifted to a higher point. It will be understood that thechain-suspension means 17 may be removed from the electrode. duringnormal operation, and whilethe latter is supported by the upper end ofthe ,electrode is the suspension means of this inven-' free to haveadditional casing sections and electrode paste added thereto from timeto time. With the suspension means of this invention, the casing is madesufllciently strong to withstand the strain and the weight placed uponit, and is sufficiently connected to the electrode mass through thetoothed aluminum ribs. In aluminum furnaces the casings are usually madefrom metallic aluminum, so that the metal'of the easing as it melts anddrops into the bath will not contaminate the latter. Since the meltingpoint of aluminum is in the neighborhood of 680 C., I take precaution toprevent the metallic ribs or internal extensions melting off before thebaking of the electrode has proceeded sulilciently above their lowerends to insure a sufficient connection between the ribs and the bakedpart of the electrodes. In accomplishing this, the casings are providedwith ribs that are relatively wide with reference to their depth in theelectrode mass, so that while they extend only a comparatively short wayinto the electrode, they afford a. wide contact surface with theelectrode paste, so that the latter is not only effectively supported,but

the ribs are kept effectively cool by reason of their wide surface areaon the outside of the easing, and by reason of the quick conduction ofthe heat to the external electrode casing. The casing itself ispreferably made relatively thick in order that its heat conductivitywill be sufficient to prevent the internal ribs from melting away atpoints too high up in the electrode.

Tests have shown that when the ribs are made in the manner that has beendescribed, they keep from melting away, even down to the very surface ofthe bath, notwithstanding that the temperature of the latter may be inthe neighborhood of 1000 C. The baking of the electrode paste, it hasbeen found, proceeds upwardly to from about twenty to about forty inchesabove the surface of the bath, so that by thus preventing the ribs frommelting away too early, a sufficient connection between the baked partof the electrode and the ribs, to insure a safe suspension of theelectrode and retention of the mass therein, is obtained.

The form of squared teeth on the inner portion of the ribs, as shown at3 in Figure 2, may also be used. In either form, the width of the ribsmay be equal to about one-fourth of their depth, as this proportion hasbeen found to aflord the advantages of'eflective support, and cooling,pointed out above.

Instead of introducing the current in the manner shown, thecurrent-conducting cables may be fixed to the external ribs at pointsunder the suspension frame, so that the ribs may be used for supplyingthe electric current to the electrode. gsreg combination of botharrangements may be The foregoing description has been given forpurposes of illustration and understanding of the invention, and noundue limitations are to be deduced therefrom, but the appended claimsshould be construed as broadly as permissible, in view of the prior art.

.Having thus described my invention what I claim is, I

1. In'an electrode of the type which is baked in the furnace in which itis used comprising a metallic casing having externally projecting ribs,the combination with the electrode of a suspension device includingclamps engaging the ribs,

9. frame on which the clamps are supported, and 1 means for raising andlowering the frame.

ids

7 1,025,354 2. A suspension device for electrodes having extemallyprojecting ribs comprising a suspension frame, a pair of clamps pivotedon the frame, and means for drawing the clamps into binding engagementwith the ribs.

3. The combination of an electrode having a casing provided with anexternally projecting rib, of a suspension frame, a pair of clampspivoted on the frame and engaging the externally projecting rib, andmeans connecting the clamps together at the point outside of the rib fordetachably maintaining the clamps in engagement with the rib. v

4. An electrode comprising a metallic casing, an electrode mass, saidcasing being provided with ribs having toothed portions projecting intothe electrode mass and having portions projecting outwardly from thecasing, in combination with a clamping device adapted to engage theoutwardly projecting portions of the ribs for suspending the electrode.

5. The combination with an electrode having a metallic casing the casingbeing provided withexternal projectingribs, of a frame surrounding theupper portion of the casing, and suspending means for the electrodeinterconnecting the external projecting ribs of the casing and theframe, whereby additional sections may be added to the upper end of theelectrode without disturbing the suspending means for the electrode.

6. In an electrode having a casing provided with externally projectingportions and including an electrode mass contained within the casing,the combination with the electrode, of means engaging the projectingportions of the casing to thereby support the electrode without exertingpressure upon the electrode mass.

'7. In an electrode of the type which is baked in a furnace in which itis used comprising a casing provided with externally projectingportions, and electrode mass contained therein, the combination of teethcarried by the casing and projecting into the mass, said teeth being ofa width and depth sufilcient to support the'electrode mass, meansengaging the projecting portions for supporting the casing without.exerting pressure on the electrode mass, and means for raising andlowering the said supporting means.

JEAN GROLEE.

